<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
    /*
      列表样式
      list-style:none;
      列表样式类型
      list-style-tpye:disc|circle|square
      列表样式图片
      list-style-image
     */
    ul{
      /*  list-style-type: disc; */
      list-style-image: url("images/icon1.png")
    }
    </style>
</head>
<body>
    <ul>
        <li>1</li>
        <li>2</li>
        <li>3</li>
    </ul>
</body>
</html>